Download it to your desktop as minecraft.jar (instead of minecraft.zip). Then go into
your explorer and at the top type in %appdata%.

Then click .minecraft, then bin. Next you need to rename your old .jar file to minecraft1.8 or whatever...as long as it's not minecraft.jar anymore. After that's done just drag the new file from your desktop into the bin file and you should be good to go.

the end has no way out :ohmy.gif: so ther need's to be a way out so you can get more thing's to live in it :smile.gif: like a wepon to kill the ender men and ender dragon's

1. Bring in renewable resources.
2. ?
3. Profit.
Just kidding, bring in saplings, dirt, seeds, lava, water and anything else you need.
Besides, I suspect that Enderdragons are required to get back to the Overworld in the next pre release.